The present invention is directed to outrigger assemblies, and more particularly to outrigger assemblies for use with dump trailers.
Dump trailers are used extensively to haul and dump a wide variety of loads, such as dirt, fill, asphalt, rocks, and the like. One essential function of a dump trailer is the ability to lift the front end of the trailer bed upwardly to tip the bed to dump its contents out through the bed""s open rear gate. When the full trailer bed is in the lowered position, the dump trailer is very stable and difficult to tip. As the full trailer bed is tilted upwardly, the dump trailer""s center of gravity moves upwardly, so the dump trailer is more susceptible to tipping. The dump trailer is also more susceptible to tipping when the bed is raised and the center of gravity shifts laterally relative to dump trailer""s longitudinal axis. Such lateral movement can occur if the dump trailer is parked on an inclined or unstable surface, or if the load within the bed shifts as the contents are being dumped from the trailer bed. If the center of gravity of the trailer bed moves outside the dump-trailer""s wheel-base, the dump trailer could tip.
The prior art has attempted to overcome the dump trailer""s susceptibility to tipping when the trailer bed is raised. One such attempt includes providing level indicators on the dump trailer to determine whether the dump trailer is level before lifting the bed. In some situations, the process of adjusting the dump trailer to a level orientation is not feasible or practical, such as on undulating terrain at a construction site. In such a situation, the level indicators can inform the user by indicating how far away the trailer is from being level.
The present invention overcomes limitations of the prior art and provides additional benefits. One embodiment of the invention provides an outrigger assembly having a mounting portion mountable to a dump trailer""s suspension system, and two stabilizing arms pivotably attached to the mounting portion. A driving mechanism is connected to the stabilizing arms and is configured to move the stabilizing arms between an inward, stowed position and an extended, stabilizing position. The stabilizing arms are shaped and sized to engage the ground outboard of the dump trailer""s wheel base to increase the effective width of the dump trailer""s support base, thereby stabilizing the dump trailer from tipping.
In one embodiment of the invention, the mounting portion is releasably attached directly to a leaf spring suspension system of the dump trailer. The stabilizing arms are pivotally attached to the mounting portion adjacent to the leaf springs. The driving mechanism for each outrigger arm is a hydraulic actuator coupled to the dump trailer""s hydraulic system. The hydraulic actuators are adapted to retract the stabilizing arms into a near vertical position adjacent to the dump trailer""s bed with the stabilizing arms inboard of the rear wheels, so the stabilizing arms do not inhibit normal operation of the dump trailer.